To call Alan Ayckbourn prolific is an understatement. “Neighbourhood Watch,” which just opened at 59E59 Theaters, is his 75th play. And since the British master is a mere 72 and spry — he often directs his own shows, including this one — we probably have at least another dozen to look forward to.

While we’re far from the heights of “House and Garden,” “The Norman Conquests” or “Absurd Person Singular,” this new comedy is a pretty decent one. It’s a must for Ayckbourn fans, as well as people who devour such Britcoms as “Keeping Up Appearances” and “The Vicar of Dibley.”

Unlike many of Ayckbourn’s works, “Neighbourhood Watch” doesn’t feature a high-concept twist. Aside from being told as a flashback, the plot’s linear. The point of view doesn’t change midway through, and there are no storytelling gambits.

Instead, the playwright has opted for straightforward satire as he introduces us to an unlikely gang of vigilantes.

When the 50-ish Martin (Matthew Cottle) and his sister, Hilda (Alexandra Mathie), move to the Bluebell Hill development, their main concern is the adjacent projects. They think young ruffians are trespassing, and some of their new neighbors only fan the flames of suspicion.

So the devoutly Christian siblings decide to take matters in their own hands and start the crime-fighting association of the title. “This is war!” Martin proclaims from behind his wire-rimmed glasses.

In no time, a hapless, cuckolded neighbor, Gareth (Richard Derrington), whips up some medieval stocks for miscreants. Hilda suggests searching cars for alcohol, and casually mentions a “morality subcommittee.” Martin, for his part, is tipsy with power — being drunk would be excessive for such a mild-mannered man.

But the projects turn out to be a red herring. As is often the case, the real problems lurk closer to home.

The cast, brought over from the original English production, is uniformly fine. Mathie shines as Hilda, a repressed woman whose high-minded intentions can badly misfire, and Frances Grey wonderfully clashes with her co-stars as the local vamp.

What’s frustrating is that you know these actors could deliver sharper blows, if given the opportunity. Ayckbourn pokes gentle fun at his earnest, misguided characters, but you wish for more bite. This is all well and good, but teeth marks would leave a deeper impression.